1. Field of the Invention
The present invention concerns a method for determining the motion of a target in underwater acoustics.
2. Description of the Prior Art
A known method in underwater acoustics to detect the position and motion of submerged targets uses a submerged movable antenna consisting, for example, of three sensors spatially separated from one another. This antenna makes it possible to measure the differences between the propagation times of a signal emitted by a moving target towards the different sensors. In most of the known devices, a description of which may be found in the article by J. C. HASSAB, B. GUIMOND, S. C. NARDONE, "Estimation Of Motion And Location Parameters Of A Moving Source Observed From A Linear Array" in the journal JASA 70(4), October 1981 or again in the IEEE communication by D. J. MURPHY, "Target Tracking With A Linear Array In An Underwater Environment", November 1981, the sensors are aligned and the intermediary sensor is placed strictly at mid-distance between the other two. However, in practice, this arrangement is difficult to meet and the faults in the alignment and position of the sensors introduce errors in the estimation of the positioning and motion of the targets.